X-ray radiation is widely used to probe the internal structure of materials in applications such as medical diagnosis, security screening, and industrial inspection. In simple imaging methods, x-ray photons are transmitted through an object. The transmitted x-ray photons collected by a recording device over a period of time to form a static projection image with overlapping structural features. More advanced imaging methods, such as computed tomography (CT), use multiple projection images from different viewing angles for image reconstruction or multiple frame images for contrast enhancement purposes.
Typical CT scanners achieve multiple viewing angles by high-speed rotation of an x-ray tube around an object. This requires a large and complicated gantry, which limits current medical CT scanners to about one second per scan. This sequential recording of x-ray images is inefficient when a large number of images of the same object are required. For example, CT scanners with a single-pixel x-ray tube take about 0.5 seconds for the x-ray tube to make one 360 degree rotation. In the process of this one rotation, about 1,000-2,000 projection images are taken. Each exposure is roughly 250-500 μs. For applications such as medical imaging, the long exposure times of current CT systems make them undesirable or ineffective.
Techniques for increasing data collection speed for single-pixel x-ray tube systems include increasing the rotation speed of the x-ray tube or increasing the x-ray flux. However, these techniques are limited by physical constraints regarding the maximal rotation speed of the x-ray tube and overheating of the anode surface.
Accordingly, in light of the above described difficulties and needs associated with x-ray imaging, there exists a need for improved methods, systems, and computer program products for multiplexing computed tomography.